We isolated cDNAs encoding flavonol synthase (FLS) from the red onion “H6” (AcFLS-H6) and the yellow onion “Hwangryongball” (AcFLS-HRB). We found three amino acid variations between the two ...sequences. Kinetic analysis with recombinant proteins revealed that AcFLS-HRB exhibited approximately 2-fold higher catalytic efficiencies than AcFLS-H6 for dihydroflavonol substrates and that both proteins preferred dihydroquercetin to dihydrokaempferol. The expression patterns of flavonoid biosynthesis genes corresponded to the accumulation patterns of flavonoid aglycones in both onions. Whereas the other flavonoid biosynthesis genes were weakly expressed in the HRB sheath compared to that of H6, the expression of FLS was similar in both onions. This relatively enhanced FLS expression, along with the higher activity of AcFLS-HRB, could increase the quercetin production in the HRB sheath. The quercetin content was approximately 12-fold higher than the cyanidin content in the H6 sheath, suggesting that FLS has priority in the competition between FLS and dihydroflavonol 4-reductase (DFR) for their substrate dihydroquercetin.
Onion, (Allium cepa L.), is one of the most consumed and grown vegetable crops in the world. Onion bulb, with its characteristic flavor, is the third most essential horticultural spice with a ...substantial commercial value. Apart from its culinary virtues, A. cepa is also used traditionally for its medicinal virtues in a plethora of indigenous cultures. Several publications have been produced in an endeavor to validate such traditional claims. Nonetheless, there is still a dearth of up-to-date, detailed compilation, and critical analysis of the traditional and ethnopharmacological propensities of A. cepa. The present review, therefore, aims to systematically review published literature on the traditional uses, pharmacological properties, and phytochemical composition of A. cepa. A. cepa was found to possess a panoply of bioactive compounds and numerous pharmacological properties, including antimicrobial, antioxidant, analgesic, anti-inflammatory, anti-diabetic, hypolipidemic, anti-hypertensive, and immunoprotective effects. Although a large number of in vitro and in vivo studies have been conducted, several limitations and research gaps have been identified which need to be addressed in future studies.
•The Greek landrace of onion “Vatikiotiko” has been described for the first time.•Morphological traits assessment showed significant differences.•Chemical composition and nutritional value have been ...characterized.•“Vatikiotiko” onion has interesting phytochemicals and nutritional value.
“Vatikiotiko” is an onion local landrace from Greece with special quality features, such as strong and pungent taste and storability. In this study, we tried for the first time to describe this landrace and record its morphological traits and nutritional value in comparison with commercially cultivated genotypes (“Creamgold”, “Red Cross F1” and “Sivan F1”). Nutritional value of “Vatikiotiko” was higher than commercial genotypes, whereas total sugars, fructose and glucose content were lower in “Vatikiotiko” and “Creamgold” onions. Fatty acids composed mostly from polyunsaturated fatty acids (linoleic and α-linolenic acid), whereas for “Vatikiotiko” saturated and monounsaturated fatty acids were detected in equal amounts (29.79% and 30.60%, respectively). “Vatikiotiko” and “Creamgold” had low antioxidant activity (DPPH radical scavenging activity), especially when comparing with “Sivan F1” and “Red Cross F1”, whereas no flavonoids were detected in “Vatikiotiko”. The overview of “Vatikiotiko” landrace supported its special character regarding its nutritional value (sugar content, mineral composition and fatty acids profile) and the necessity to revalorize and protect its traditional culture. The potential of introducing it as Protected Designation of Origin (PDO) or Protected Geographical Indication (PGI) product has also been discussed.
Onion‐like NiCo2S4 particles with unique hollow structured shells are synthesized by a sequential ion‐exchange strategy. With the structural and compositional advantages, these unique onion‐like ...NiCo2S4 particles exhibit enhanced electrochemical performance as an electrode material for hybrid supercapacitors.
Zn‐based electrochemical energy storage (EES) systems are attracting more attention, whereas their large‐scale application is restricted by the dendrite and parasitic reaction‐caused unstable Zn ...anodes. Herein, a negatively charged hydrophobic carbon nano‐onion (CNO) interfacial layer is proposed to realize ultrastable and high‐rate Zn anodes, enabling high‐performance Zn‐based EES. For the CNO interfacial layer, its hydrophobicity not only blocks active water but also reduces the Zn2+ desolvation barrier, and meanwhile, the negatively‐charged CNO nanoparticles adsorb Zn2+ and repel SO42− to homogenize Zn2+ flux, accelerate Zn2+ desolvation and suppress the self‐corrosion of Zn anodes. Besides, the conductive CNO interfacial layer increases the surface area for the Zn deposition to reduce local current density. Consequently, under the modulation of the CNO interfacial layer, Zn plating/stripping exhibits impressive reversibility with an average Coulombic efficiency of 99.4% over 800 cycles, and Zn anodes present significantly enhanced electrochemical stability and rate performance, whose operation lifetime exceeds 2000 h at 1 mA cm−2 and 350 h even at 10 mA cm−2. Moreover, high‐rate and ultralong‐life Zn‐ion hybrid supercapacitors are achieved with the CNO interfacial layer‐modulated Zn anode and activated CNO cathode. This work provides new thinking in regulating the Zn deposition interface to realize high‐performance Zn‐based EES.
A negatively charged hydrophobic carbon nano‐onion (CNO) interfacial layer to realize ultrastable and high‐rate Zn anodes is reported, enabling high‐performance Zn‐based electrochemical energy storage. Its hydrophobicity blocks active water and reduces the Zn2+ desolvation barrier, and the negatively charged CNOs adsorb Zn2+ and repel SO42− to homogenize Zn2+ flux, accelerate Zn2+ desolvation and suppress the self‐corrosion of Zn anodes.
The main results of research on onion crops in the laboratory of seed selection and technology of cultivation of vegetable cultures of SibNIIRS for a 40-year period are given. Collection, study and ...reproduction of local and varieties from other regions made it possible to create an extensive gene pool of onion plants for various breeding and direct use in production. More than 1500 samples belonging to 52 species of the genus Allium have been studied. The following species are most developed in the selection plan: shallots, shnitt, batoon, slizun, fragrant, Altai. The advantages of cultivation of shallots onions in comparison with onion are shown. The main methods of selection of onion cultures are presented in the historical section. As a result of selection, polycross and interspecific hybridization (A. ascalonicum x A. cepa), 15 sorts of shallots of different maturation period have been created and entered into the State Register. The most productive were the hybrid populations, where the sorts of shallots were used as maternal forms: the bulb weight increased, the number of them in the nest decreased, and they were more evenly sized. The advantage of the landing of the shallows in the nursery of competitive variety testing is shown. A clonal nursery of rhizome perennial onions was created in 5 species, numbering 330 samples (shnitt, Altai, slizun, baton, fragrant). Interest for selection on a set of economic features is 19 (productivity of seeds and green leaves, intensity of regrowth after cut, qualitative composition of leaves, resistance to diseases).
Onion is the one of the important vegetable crops cultivated in India. Multiplier type onion is one among the three major types of onions. Tamil Nadu accounts for five per cent of country’s area ...under onion and more than 70 per cent of the area is cultivated by small onion (Allium cepa var. aggregatum). Around 90 per cent of country’s multiplier onion is produced from Tamil Nadu. Detopping is one of the steps in the on-farm processing carried out after harvest. Presently this is done manually by farm women. Individual onions are picked and detopping is done by using sickle. This operation is time consuming and highly drudgery in nature. An Onion detopping machine to remove the foliage after harvest was designed and developed in the present study. This machine has a capacity of 370 kg/h against 30 kg/h manual practice and works with an efficiency of 98%. The unique design of the detopper is that it is suitable for all sizes of onions. Also, the cluster is intact after detopping, which is very important requirement. This multiplier type onion is grown in Nagamangala (Tk), Mandya (Dt.) of Karnataka State. Two farmers of this area have installed this machine and running a successful enterprising. Cost involved in using this machine is Rs. 200 per quintal against Rs. 500 per quintal by manual detopping. Owing to the higher capacity by mechanization, the farmers will be able to process the higher volume of produce within a short span of time. Hence, this will facilitate the farmers to sell the produce, get good market price and earn higher returns.
Potassium‐ion batteries (PIBs) have been regarded as a competitive alternative for lithium‐ion batteries, owing to the natural abundance, low cost, and similar rocking‐chair working mechanism of ...potassium element. However, it is challenging to simultaneously prepare suitable potassium ion anode materials of low voltage plateau, high capacity, and long cycle life. In this work, onion‐like soft carbon (OLSC) of high heteroatom content is prepared by using solvent‐sensitive self‐assembly properties of asphaltene molecules. The OLSC electrode exhibits a low voltage plateau because of a high degree of graphitization. Meanwhile, it possesses excellent cycling stability and rate capability due to the high stability of the onion‐like structure and fast transport of potassium ions, the latter of which is caused by heteroatom‐induced expanded interlayers as found by first‐principle calculations. Compared with existing carbon materials, the OLSC synthesized in this study exhibits a high reversible capacity of 466 mAh g–1 at 20 mA g–1, a reversible capacity of 222 mAh g–1 and capacity retention of 95% after 1600 cycles at 1 A g–1. This work connects the nanostructure of carbon materials and electrochemical performance and provides new insights in improving carbon‐based anodes for PIBs.
It is challenging to simultaneously prepare suitable potassium ion anode materials of low voltage plateau, high capacity, and long cycle life. Onion‐like soft carbon (OLSC) of high heteroatom content is prepared by using solvent‐sensitive self‐assembly properties of asphaltene molecules. The OLSC electrode exhibits a low voltage plateau, excellent cycling stability, and rate capability.
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